Gearing code?

[tderose]

Hey guys, quick question about the gearing code on the door jamb. I have a 1998 Tacoma 4x4 2.7L reg cab 5 spd. Trying to figure out my gear code. I know the B03A means 8 inch ring gear, 4.10's, 2 pinion, open diff. That's what I was looking for, but I can't find it anywhere on my door jamb code. I'm pretty confused now...I know a guy who has the same truck, but in a '99 model, and he has the BO3A code. My stock tire size says 225/75/15 I think, but on the axle code it has a ? - question mark...like they didn't know what the heck they put into the axles on this thing? Below is a link to the pic I took of my door jamb codes along with a pic of my truck. Please help me interpret if you can read it clearly. See the ? symbol there, what the heck is that? Don't tell me I have 3.58's I'll forget about modifying this thing and put it on the market tomorrow if I do. I want to go to 32's after the OME install, but if I have 3.58's, I'll have to regear to perhaps 4.56's to sufice. I'll stay with the 4.10's for a while until I can save up for 4.56's and a Lockrite for the rear if that's what I have. PLease help!

http://s62.photobucket.com/albums/h8...gAnch=imgAnch1

http://s62.photobucket.com/albums/h8...gAnch=imgAnch7

[TacoDell]

http://www.tacomaterritory.com/wiki/...php/Gear_Codes

?? = 3:91's.... maybe... LOL

[88toy4x4]

From what I can tell, you have 4.10's. I do not see a gear code but I do see the model number RZN161L-TRMDKAB. Looking at the model code and This Website, I come up with 4.10's for your truck if it came with the 31's from the factory. 3.58's are listed for that model number, too . From my experience and looking around, I have never seen a 4cyl regular cab 4x4 older than 2000 with anything less than 4.10's. That is by no means a fact - take it for what it is worth. Every 4x4 tacoma that has 3.58's, I have found has been a 4cyl extended cab.(Including mine )

You can always jack up the truck and spin the driveshaft and count tire revolutions. There are different ways to do it - Search. There have been a few how-to's on the forums. Hope this helps.

[Iggy]

Originally Posted by TacoDell

http://www.tacomaterritory.com/wiki/...php/Gear_Codes

?? = 3:91's.... maybe... LOL

ok my says B03A but i have the rear diff locker ?

[tderose]

Thank you guys for your replies! 88toy4x4, you gave me some much needed confidence. My truck came with 265's x 75 x 15's which measure 30.65 inches which is technically a 31" tire even though my door jamb sticker says 225x75x15. It must have been a factory option for the regular cabs? I will do the driveshaft revs thing. I think Hytenor or showstop has some info about that in another thread! Is this any indicator? My truck pushes the 265's with no problem and the fastest I've ever had this truck is just slightly over 90 on I-95! Overdrive woks great and I do not have to downshift from overdrive into 4th when scaling the mountains in Virgina! I've made no performance mods to the truck except a drop in K & N filter. Plan on doing to deckplate mod soon though. Keep the posts coming! Thanks again!

- Tony

[ShowStop]

Wow, your sticker just has a ? where the axle code would be. Look at the bottom right of the sticker. The code A/TM is for axle/transmission and the part after is blank. Guess they didn't know what was in it when the VIN sticker was printed.

[tderose]

I guess I'll just have to do the driveshaft revs and try it that way. Is there a formula for figuring it out??? I'm sure I have an open diff in the rear, so I would only need to jack up one side of the vehicle. Thanks!

[Iggy]

i guess they fucked up on my too

[tderose]

Originally Posted by Iggy

i guess they fucked up on my too

Do you have the same ? - symbol for your Transmission/axle code? I wonder what the heck that means? Show stopm was puzzled by it as well. I wonder if Hytenor has ever seen this before or know what it means? My truck came with the 15x7JJ wheels and 265's stock, so according to the list of model numbers and options 88toy4x4 gave me in post #3, I have 4.10's! The driveshaft revs is the only true way to tell, but I don't quite know what formula to use. How many turns of the wheel, etc.?

[Iggy]

Originally Posted by tderose

Do you have the same ? - symbol for your Transmission/axle code? I wonder what the heck that means? Show stopm was puzzled by it as well. I wonder if Hytenor has ever seen this before or know what it means? My truck came with the 15x7JJ wheels and 265's stock, so according to the list of model numbers and options 88toy4x4 gave me in post #3, I have 4.10's! The driveshaft revs is the only true way to tell, but I don't quite know what formula to use. How many turns of the wheel, etc.?

no it just the code if diffrent from what i have code says i have no rear locking diff but i do from factory

[hytenor]

Originally Posted by Iggy

ok my says B03A but i have the rear diff locker ?

TRD? then you should have 4.10s with the AT and possibly 4.30s with a manual

[hytenor]

Originally Posted by tderose

Thank you guys for your replies! 88toy4x4, you gave me some much needed confidence. My truck came with 265's x 75 x 15's which measure 30.65 inches which is technically a 31" tire even though my door jamb sticker says 225x75x15. It must have been a factory option for the regular cabs? I will do the driveshaft revs thing. I think Hytenor or showstop has some info about that in another thread! Is this any indicator? My truck pushes the 265's with no problem and the fastest I've ever had this truck is just slightly over 90 on I-95! Overdrive woks great and I do not have to downshift from overdrive into 4th when scaling the mountains in Virgina! I've made no performance mods to the truck except a drop in K & N filter. Plan on doing to deckplate mod soon though. Keep the posts coming! Thanks again!

- Tony

with factory 265s you should have 4.10s for a '99, especially for what your plate shows...4-98. 4.30s if it was a '00

[tderose]

Originally Posted by hytenor

with factory 265s you should have 4.10s for a '99, especially for what your plate shows...4-98. 4.30s if it was a '00

Hytenor, do you know how to do the driveshaft revs (counting, marking the driveshaft, marking the tire) formula? Someone said you have a old thread that covers this, but I can't find it using the search function. Based upon the replies, and maintained performance of my truck with the 265's, I'm almost certain I have the 4.10's. Thanks for your replies everyone! I feel a little better about this now.

Originally Posted by 88toy4x4

have never seen a 4cyl regular cab 4x4 older than 2000 with anything less than 4.10's. That is by no means a fact - take it for what it is worth. Every 4x4 tacoma that has 3.58's, I have found has been a 4cyl extended cab.(Including mine )

I'm surprised that they would put such high gearing in the extended cab models with the longer wheelbase and the added weight? Reg cabs got 4.10's and the heavier ext cabs got 3.58's? What's the logic behind that?

[hytenor]

Originally Posted by tderose

Hytenor, do you know how to do the driveshaft revs (counting, marking the driveshaft, marking the tire) formula? Someone said you have a old thread that covers this, but I can't find it using the search function. Based upon the replies, and maintained performance of my truck with the 265's, I'm almost certain I have the 4.10's. Thanks for your replies everyone! I feel a little better about this now.



I'm surprised that they would put such high gearing in the extended cab models with the longer wheelbase and the added weight? Reg cabs got 4.10's and the heavier ext cabs got 3.58's? What's the logic behind that?

3.58s were designed for a 28" (225) tire, not a 29 (235) or 31" (265).
the chart also shows one early v6 model with 225 size tires and 3.15 gears It seems that if a truck was factory equiped with the tire upgrade they upped the gears as well. trucks that got tires upgraded at the dealership didn't get the gear change. My '00 plate shows 235 size tires but the window sticker shows the factory optional 265s, hense the 4.30 gears rather than 3.91s


as for finding your ratio.

jack up one rear corner, making sure to block the front tires, make a chalk mark or use something that will be easily seen on both the tire and the rear driveshaft. spin the wheel 10times while counting the revolutions on the driveshaft. you can get a close estimate with one wheel turn too.

41 ds turns to 10 wheel turns = 4.10:1

[tderose]

Thanks, I'm going to do the driveshaft revs tomorrow! Thanks for formula!